Do sexual gonadic maturity and age determine habitat occupancy ofCanthon cyanellusLeConte, 1859 (Coleoptera: Scarabaeidae)?

Abstract

High-quality habitats presumably have the resources required to sustain relatively high rates of survival and reproduction. We assessed how habitat type and local environmental conditions determine the distribution of individuals of Canthon cyanellus (Coleoptera: Scarabaeidae), an eurytopic dung beetle, according to age category and sexual gonadic maturity. Beetles were surveyed in forest fragments, live fences, and pastures in Mexico. Individuals were categorised into six age categories according to the glandular volumes in males and oocyte number and length in females. Mature females in forest fragments were the most abundant females found among the habitats. Air humidity and soil hardness were positively and negatively related to mature female abundance, respectively. Mature beetles were the most abundant among males, and higher abundance of males occurred in forest fragments than in live fences and pastures. Light quantity was negatively related to the abundance of young males. Compared to forest fragments, females in pastures had larger oocytes. However, sites with higher soil hardness and air humidity had females with lower numbers of oocytes. Our results demonstrate that, although C. cyanellus occurs across a wide range of habitats, forest habitats might host sexually mature individuals, which translates into more effective individual dispersion and potential reproduction.

Not all dung beetles feed on dung: Scarabaeinae (Coleoptera: Scarabaeidae) attracted to different carrion types in contrasting habitats at Brazilian Amazon

“…Since that dung beetles are able to select a specific food type using olfactory cues (Dormont et al 2010; Stavert et al, 2014), this fact can help to explain why decaying beef was more attractive than decaying liver in our study. However, further studies assessing the volatile and nutritional compounds of each carrion type ( see Frank et al, 2017) are needed to clearly understand the process of carrion choice by dung beetles in tropical landscapes. Cattle beef maintains more stable populations: as observed previously, dung beetle population may present intraspecific segregation of their populations facing different food resources and microhabitat conditions (Salomão et al, 2021; Salomão et al, 2022). Therefore, it is possible that cattle beef maintains more stable populations than cattle liver.…”

“…Cattle beef maintains more stable populations: as observed previously, dung beetle population may present intraspecific segregation of their populations facing different food resources and microhabitat conditions (Salomão et al, 2021;. Therefore, it is possible that cattle beef maintains more stable populations than cattle liver.…”

“…In this sense, carrion could be considered an optimal resource for those beetles that require food resources that are available for longer periods. Higher abundance in dung beetle population may be associated to a preference for specific spatial and trophic resources (Salomão et al, 2021, 2022). Although our data has a limited sampling effort (40 pitfall traps, 20 for each carrion type), the results presented herein give cues suggesting that a segregation and preference at population scale for specific carrion types among dweller dung beetles.…”

The conversion of native savannah into pasturelands does not affect exclusively species diversity: Effects on physiological condition of a highly abundant dung beetle species

“…Thus, food quality could be increasing muscle mass of pasture P. palaeno compared to Cerrado ones. A second hypothesis is that environmental conditions may filter dung beetle intraspecific traits (Giménez-Gómez et al, 2020;Salomão et al, 2021).…”

“…The contrasting results observed herein provide a heterogeneous scenario, with individuals from each habitat presenting clearly distinct physiological condition. In a study performed in southern Mexico, individuals of Canthon cyanellus LeConte, 1859 apparently presented a population segregation according to physiological condition, age, and sex among habitat types (Salomão et al., 2021), suggesting that individuals could selected the best suited habitat according to their individual condition. To better understand how populations of dung beetles move across habitats and how their body masses are used and change throughout time, mark recapture and long‐term studies should be addressed.…”